The Doosan NHP-4000 is a 4-axis CNC horizontal machining center with a reputation for dependable, high-throughput production that has made it a staple in job shops and contract manufacturing cells. This 2021 unit carries twin 400 mm (15.7 inch) square pallets on an automatic pallet changer, X / Y / Z travels of 22 x 25.2 x 26 inches, and 2,362 ipm rapid traverse on all three linear axes. Pallet surface to spindle center ranges from 3.1 to 28.3 inches, and the work envelope accepts parts up to 24.8 inches in diameter by 35.4 inches tall. The 15,000 RPM, 40 HP CAT 40 Big Plus spindle is served by a 60-tool automatic tool changer with a 0.9 second tool-to-tool change, handling tools up to 3.0 inches in diameter (6.7 inches with adjacent pockets empty), 17.7 inches long and 26.5 lbs. A 0.001 degree N/C rotary table provides full 4th axis positioning, supported by tilted work plane programming and pallet clamp confirmation. Control is a Fanuc 31i-B color CNC with EZ Guide i conversational programming, AI Contour Control II with a 200-block high-speed CPU, Nano Smoothing, helical interpolation, thread cutting with synchronous feed, 8 MB part program storage, 200 pairs of work offsets, embedded Ethernet, Doosan tool load monitoring and a handheld MPG. Coolant includes 300 PSI coolant through the spindle plus shower coolant, with an LNS chip conveyor and an LNS Fox WS 2 700 mist collection system.
Compared with the earlier Doosan HP 4000 horizontal, the NHP-4000 was engineered as a faster 400 mm-class production platform. It standardizes a 15,000 RPM spindle and 2,362 ipm rapids on all three axes, pairs them with a servo-driven tool changer and quick pallet exchange that trim non-cutting time, and moves to the Fanuc 31i-B control with AI Contour Control II and Nano Smoothing for smoother high-speed contouring. The result is a meaningfully better machine, not just a newer one: more spindle time per shift and finer finishes on complex prismatic parts than the older HP-series horizontal it replaced.